1. Field of the Invention
The present invention relates to power plants. More specifically, the present invention relates to methods and apparatus for a non-polluting turbo-charged power plant having a liquid fuel burning chamber for the combustion of hydrocarbon based fuels.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
Many different types of liquid fueled power plants are known in the art for providing thrust to, for example, propel a projectile or drive a generator. Examples include liquid fueled jet engines, piston engines and rocket motors of various designs. Each of these liquid fueled power plant designs suffer from a number of problems during the launch and flight stages of the projectile or when driving the generator. The problems common to liquid fueled power plant designs include the generation of excessive amounts of noise and heat. Also, in the case of a liquid fueled rocket motor, large amounts of smoke can be generated which results in increased levels of atmospheric pollution.
Low detectability of a projectile during target approach is necessary in stealth operations. However, the generation of excessive noise during the launch and flight stages increases the probability that the projectile will be detected upon approach. Likewise, generation of large amounts of heat by the projectile can be detected by infrared sensors such as the forward looking infrared devices utilized by aircraft. The heat generated by the projectile can also be detected visually by utilizing night vision goggles. The smoke generated by certain liquid fueled rocket motors creates a visual smoke trail. Thus, the projectile is easier to track and the origin of the launch point is easier to determine. The density of the smoke trail is dependent upon the type of rocket motor fuel employed. Each of these problems increase the probability of projectile detection during approach to the target. Likewise, when driving a generator with, for example, a liquid fueled piston engine, the smoke exhaust from the engine increases the atmospheric pollution level.
The use of a turbocharger or supercharger in combination with a liquid fueled power plant is known. In particular, the use of a turbocharger in combination with a turbine jet engine, piston engine or turbine rocket motor capable of providing thrust to propel a projectile is also known. In general, the use of a turbocharger in combination with any of the above mentioned power plants affords control of the direction of the hot expanding exhaust gases of the power plant, increases the volume of the hot expanding exhaust gases, and provides oxidation of the liquid fuel under pressure.
A turbine jet engine has a long cylindrical body and includes one or more liquid fuel burning chambers. The burning chambers are located at the center of the long cylindrical body and normally burn at temperatures in excess of three-thousand degrees Fahrenheit. The turbine jet engine includes multiple compression stages comprising a turbine or turbocharger located in the forward section of the jet engine. The turbocharger produces a very high pressure in the burning chambers. When the liquid fuel is injected into the burning chamber, the fuel is combusted to provide hot, high pressure gases. A high percentage of the output gases are fed back and utilized in a control loop to drive the turbine wheel. The balance of the output gases are used to perform useful work such as driving an aircraft or missile.
The outer walls of the jet engine burning chamber are at a lower temperature than that of the flame at the center of the burner. Because of the temperature differential between the flame and the outer wall and the operating temperature of the burning chamber, the liquid fuel, which is generally a hydrocarbon based fuel, is not totally combusted. When particles of a hydrocarbon based fuel are not totally burned, hydrocarbon based pollutants are produced. Further, since the liquid fuel is not totally combusted, the turbine jet engine is not fuel efficient. Additionally, the turbine jet engine is very noisy, expensive to build and produces excessive heat. Each of these characteristics of turbine jet engines increases the detectability of a projectile and the pollution level of the atmosphere.
Liquid fueled piston engines employing turbochargers are used in air vehicles while liquid fueled piston engines utilizing turbochargers or superchargers are used in stationary drive applications. As an example, the turbine associated with a turbocharger is located external to the piston engine block in a position normally occupied by a carburetor. Hot exhaust gases and ambient air are each fed to the turbine which compresses the gas mixture. The compressed gas mixture enables a higher volume of air to be fed to the designated piston chamber. The compressed air (e.g., greater than one atmosphere) is mixed with liquid fuel and ignited to provide a greater force then otherwise available to the crankshaft of a piston engine. Use of a turbocharger in a liquid fueled turbine rocket motor (e.g., a turbine jet engine in a rocket) is also known. The turbocharger is employed to generate and feed high volume compressed air to one or more combustion chambers. The pressurized air forces a higher volume of air into the fixed volume combustion chamber. The higher pressure exhaust gas of the combustion chamber is used to drive the turbine wheel in a feedback control loop. Both the liquid fueled piston engine and the turbine rocket motor are very noisy. Therefore, a projectile propelled by either power plant can be tracked by an audible sensor. Further, depending upon the type of liquid fuel employed in the piston engine and the rocket motor, large amounts of smoke can be generated which results in increased levels of atmospheric pollution.
Another example of a liquid fuel power plant design of the prior art is an incinerator employed for destroying hazardous waste. The incinerator includes a cylindrical combustion chamber joined by a flat circular plate to a smaller inlet pipe. Fuel nozzles protrude through the flat plate into the combustion chamber. The incinerator includes a blower air input which can be comprised of an impeller blade type air compressor. The function of the blower air input is to provide an oxidizer to mix with the liquid fuel to promote combustion. The oxidizer can also be provided by a turbocharger, a supercharger or similar device.
The air and fuel are not premixed but instead are injected into the incinerator combustion chamber at the point of flame stabilization. The fuel is ignited and the combustion chamber is heated to operating temperature. The hazardous waste material to be combusted is then delivered to the combustion chamber by fuel injectors. Total combustion of the fuel is ensured by recirculation of the gas and air mixture. Thus, low nitrous oxide (NO.sub.x) levels are produced. The heat generated by the combustion is released to the atmosphere through a long exhaust tube. The incinerator is intended only to destroy hazardous waste material and thus, is not a power plant capable of providing thrust to propel a projectile or otherwise performs useful work. Another device suitable for use with the incinerator for providing the oxidizer to mix with the liquid fuel is a motor driven radial outflow compressor. The radial outflow compressor is not driven by the exhaust gases of the combustion chamber. Normally, an alternative power source such as an electric motor or a piston or rotary engine is employed to drive the radial outflow compressor.
Thus, there is a need in the art for improvements in the design of liquid fueled power plants to reduce the detectability of and the exhausted pollutants from the power plants.